7C Populations in Ecosystems Flashcards
Ecosystem
All organisms living in a community and all of the abiotic conditions
Biotic
All of the living features of an organism
Abiotic
All of the non-living features of an organism
Habitat
The place where an organism lives
Niche
The role of a species within its habitat, for example what it eats and where it feeds
Biotic interactions- organisms it eats
Abiotic interactions- temperature range an organism can live in
Adaptation
A feature that increases their chance of survival and reproduction
Natural Selection
Better adaptations, more likely to survive and pass on the advantageous alleles
Interspecific competition
Organisms of different species compete with each other for the same resources
Intraspecific competition
Organisms of the same species compete with each other for the same resources
Predation
An organism kills and eats another organism
Methods for investigating populations
Quadrats, transects, mark release recapture
What is the equation to do with mark-release-recapture
Total population size= (number caught in 1st sample x number caught in 2nd) / Number marked in second sample
What are the assumptions that must be made in order for the mark- release- recapture method to be accurate?
The marked sample has had enough time to mix back into the population
The marking hasn’t affected the individuals chance of survival
There have been no changes in population size due to births, deaths and migration
Dynamic ecosystem
The ecosystem is constantly changing
Succession
The process by which an ecosystem changes over time
Primary succession
Succession that takes place on land that has been newly formed or exposed
Pioneer species
The first species to colonise an area. Must be adapted to grow under the harsh abiotic conditions The pioneer species then alter the abiotic conditions, making them less hostile so new organisms can start to live there
Climax community
The largest and most complex community of plants and animals that an ecosystem can support
Secondary succession
Takes place on land that has been cleared of all plants but where soil still remains- pioneer species are usually larger plants e.g shrubs
Plagioclimax
Succession is stopped artificially by humans, preventing a climax community from developing, e.g mowing lawn
Climactic Climax
The climax community for a particular climate
Conservation
The protection and management of species and habitats in a sustainable way
What are five methods of conservation?
Management of succession, seed banks, captive breeding, fishing quotas and protected areas
How does managing succession aid in conservation?
Preventing succession preserves an ecosystem in its current stage of succession
How do seed banks aid in conservation?
A store of seeds from lots of different plants. If plant becomes extinct, they can be reintroduced
How does captive breeding aid in conservation?
Breeding animals in controlled environments, which increases their numbers, and prevents the species from becoming extinct
